266 Orthorrhapha brachycera. 



Geographical distribution: — Europe; towards the north to north- 

 ern Sweden, and in Finland. 



2. T. nubila Meig. 



1804. Klass. eur. zweifl. Ins. I, 239, 9. {Tachydromia). — 1860. 

 Loew, Zeitschr. fur Entom. Breslau, XIV. 12, 2. — 1903. Kat. palåarkt. 

 Dipt. II, 275. — Tachydromia nervosa: 1822. Meig. Syst. Beschr. III, 72, 

 8. — 1862. Schin. F. A. I, 94. — Tachypeza nervosa: 1838. Meig. Syst. 

 Beschr. VII, 59, 9. — 1842. Zett. Dipt. Scand. I, 317, 6. — Tachydromia 

 truncorum, (non Fall.) : 1822. Meig. Syst. Beschr. III, 71, 6. — Tachypeza 

 truncorum (non Fall.): 1838. Meig. Syst. Beschr. VII, 95, 7. 



Male. Vertex and frons grey; palpi yellowish, with black bristles 

 at the apex. Occiput grey, with a few black bristles above, and 

 dense white hairs below. Antennæ yellow, apex and the arista 

 generally dark. Thorax brownish grey pruinose, duU; there are 

 two black notopleural bristles. Scutellum with two black marginal 

 bristles. Pleura brownish grey pruinose. Abdomen black, somewhat 

 shining, sometimes brownish black; it has very short, pale hairs. Ven- 

 ter similarly coloured and haired, but the hairs towards the apex 

 darker; the last ventral segment with longer, dark hairs. Legs paler 

 or darker yellow, front femora with a dark patch above or on the 

 posterior side and with a black stripe below, middle and hind femora 

 more or less brownish on the apical part; front tibiæ black except 

 the base, and the base of the front metatarsi black, hind tibiæ with 

 the apex black and with a more or less distinct, brownish ring near 

 the base. The front tibiæ are straight, considerably thickened, the 

 middle tibiæ straight. The legs are short-haired with yellowish hairs; 

 the middle coxæ and the base of the middle femora with a few 

 black bristles, the front coxæ with a spine at the apex on the posterior 

 side. Wings slightly brownish; the cubital and the basal part of the 

 postical vein with a broad seam. Veins brown or blackish. Halteres whit- 

 ish yellow. 



Female. Similar to the male, but the front femora with no black 

 stripe below, the front tibiæ less thickened and the metatarsi not 

 black at the base. 



Length 2,8—3,5 mm. 



This species is easily distinguished from fnscipennis besides by the 

 colour of the wings also by the very different shape of the front 

 tibiæ. 



T. nubila is very common in Denmark, running on the stems of 

 trees; vicinity of Copenhagen, Hellerup, Ordrup Mose, Dyrehaven, 

 Bøllemosen, Geel Skov, Tyvekrog, Tisvilde and at Sorø; on Langeland 



